In flight transfer of packages between aerial drones

ABSTRACT

Aspects include a system for transferring a payload between drones. The system includes a first drone having a first member and a first controller, the first member having a first coupling device on one end, the first member being configured to carry a payload, the first controller being configured to change a first altitude and orientation of the first drone. A second drone includes a second member and controller, the second member having a second coupling device on one end, the second member being configured to receive the payload, the second controller being configured to change a second altitude and orientation of the second drone. The controllers cooperate to change at least one of first and second orientations to operably engage the first coupling device to the second coupling device for transferring the payload from the first member to the second member.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of U.S. patentapplication Ser. No. 14/987,155 filed on Jan. 4, 2016.

BACKGROUND

The present invention relates generally to a system and method fortransferring packages and, more specifically, to a system and method fortransferring packages between autonomous drones or unmanned aerialvehicles during flight.

Autonomous drones, also referred to as unmanned aerial vehicles (UAVs)and remotely piloted aircraft (RPA), are expected to be ruled eligiblefor use by private and corporate entities subject to pending toregulations implemented by various aviation authorities such as, forexample, the Federal Aviation Admiration (FAA). Proposed uses for dronesinclude, but are not limited to, city ordinance enforcement, othergovernment functions, package delivery, and image capturing. Therefore,it is envisioned that users could purchase drones to achieve a certainset of needs or tasks such as delivering a payload from a warehouse to acustomer.

SUMMARY

Embodiments include a system for transferring a payload from anoriginating drone to a receiving drone. The system includes a firstaerial drone having a first transfer member and a first controller, thefirst transfer member having a first coupling device on one end, thefirst transfer member being configured to carry a payload, the firstcontroller including a processor configured to change a firstorientation of the first aerial drone. A second aerial drone has asecond transfer member and a second controller, the second transfermember having a second coupling device on one end, the second transfermember being configured to receive the payload, the second controllerincluding a processor configured to change a second orientation of thesecond aerial drone. Wherein the first controller and the secondcontroller cooperate to change at least one of the first orientation andthe second orientation to operably engage the first coupling device tothe second coupling device for transferring the payload from the firsttransfer member to the second transfer member while the first aerialdrone and second drone are in-flight.

Further embodiments include an aerial drone. The aerial drone having afuselage and a plurality of thrust producing devices coupled to thefuselage. A transfer member is coupled to the fuselage, the transfermember configured to move a payload to a second aerial drone. Acontroller is operably coupled to the plurality of thrust producingdevices, the controller including a processor that is responsive toexecutable computer instructions to adjust the plurality of thrustproducing devices to change an orientation of the transfer member tomove the payload to the second aerial drone.

Still further embodiments include a method of in-flight transferring ofa payload between aerial drones. The method includes providing a firstaerial drone having a first transfer member. A second aerial drone isprovided having a second transfer member. An orientation is changed forat least one of the first aerial drone and the second aerial drone toposition the first transfer member adjacent the second transfer member.The payload is moved from the first aerial drone to the second aerialdrone.

Additional features are realized through the techniques of the presentinvention. Other embodiments and aspects of the invention are describedin detail herein and are considered a part of the claimed invention. Fora better understanding of the invention with the features, refer to thedescription and to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter which is regarded as the invention is particularlypointed out and distinctly claimed in the claims at the conclusion ofthe specification. The forgoing and other features of embodiments of theinvention are apparent from the following detailed description taken inconjunction with the accompanying drawings in which:

FIG. 1 depicts a block diagram of an autonomous drone in accordance withan embodiment of this disclosure;

FIG. 2 depicts a block diagram of a controller for an autonomous dronein accordance with an embodiment of this disclosure;

FIG. 3 depicts a perspective view of a package delivery system using anautonomous drone in accordance with an embodiment of this disclosure;

FIG. 4, FIG. 5, FIG. 6, and FIG. 7 depict an in-flight payload transfersequence between a pair of autonomous drones in accordance with anembodiment of this disclosure;

FIG. 8 depicts an autonomous drone having a dynamic counterbalancingsystem in accordance with an embodiment of this disclosure;

FIG. 9 depicts an autonomous drone having another dynamiccounterbalancing system in accordance with an embodiment of thisdisclosure;

FIG. 10 depicts an in-flight package transfer of a payload between apair of autonomous drones in accordance with an embodiment of thisdisclosure;

FIG. 11 depicts a transfer member coupling arrangement for use with apair of autonomous drones in accordance with an embodiment of theinvention;

FIG. 12A, FIG. 12B and FIG. 12C depict a transfer member couplingarrangement for use with a pair of autonomous drones in accordance withan embodiment of the invention;

FIG. 13A and FIG. 13B depict a transfer member coupling arrangement foruse with a pair of autonomous drones in accordance with an embodiment ofthe invention;

FIG. 14A, FIG. 14B, FIG. 14C and FIG. 14D depict a transfer membercoupling arrangement for use with a pair of autonomous drones inaccordance with an embodiment of the invention;

FIG. 15A, FIG. 15B, FIG. 15C and FIG. 15D depict a transfer membercoupling arrangement for use with a pair of autonomous drones inaccordance with an embodiment of the invention;

FIG. 16 depicts another transfer member coupling arrangement for usewith a pair of autonomous drones in accordance with an embodiment of theinvention;

FIG. 17 depicts an in-flight transfer of a payload between a pair ofautonomous drones in accordance with an embodiment of this disclosure;

FIG. 18A, FIG. 18B, FIG. 18C and FIG. 18D depict an in-flight sequenceof the transfer of a payload between the pair of autonomous drones ofFIG. 17;

FIG. 19A, FIG. 19B, FIG. 19C and FIG. 19D depict an in-flight sequencefor securing the payload transferred between the pair of autonomousdrones of FIG. 17;

FIG. 20 depicts a pair of autonomous drones having tilting rotors inaccordance with some embodiments of this disclosure;

FIG. 21 depicts a flow diagram of a method of in-flight transfer ofpayloads between a pair of autonomous drones in accordance with someembodiments of this disclosure; and

FIG. 22 depicts another flow diagram of a method of in-flight transferof payloads between a pair of autonomous drones in accordance with someembodiments of this disclosure.

DETAILED DESCRIPTION

Embodiments of the present disclosure are directed to a system forin-flight transferring of packages or payloads between a pair ofautonomous drones. Embodiments of the present disclosure provide for thedelivery of a payload beyond the range or authorized area of operationfor a single autonomous drone. Some embodiments of the presentdisclosure further provide for cooperation between multiple autonomousdrones in the delivery of a payload from an originating location, suchas a warehouse for example, to a final destination, such as a customer'shome for example.

Referring now to FIG. 1, an embodiment is shown of an autonomous drone20 or unmanned aerial vehicle. As used herein, the term “drone” refersto an aerial vehicle capable to operating autonomously from a humanoperator to perform a predetermined function, such as deliver a payloador package for example. The drone 20 includes a fuselage 22 thatsupports at least one thrust device 24. In an embodiment, the drone 20includes a plurality of thrust devices 24A, 24B, such as four thrustdevices arranged about the periphery of the fuselage 22. In anembodiment, the thrust devices 24 include propeller member that rotatesto produce thrust. The thrust devices 24 may be configurable to provideboth lift (vertical thrust) and lateral thrust (horizontal thrust). Thevertical and horizontal components of the thrust allow the changing ofthe altitude, lateral movement and orientation (attitude) of the drone20.

In the exemplary embodiment, the fuselage 22 and thrust devices 24 aresized and configured to carry a payload 26 or package. The payload 26being releasably coupled to the fuselage 22 by a first tether 28. Aswill be discussed in more detail herein, the payload 26 may also becoupled to a second tether 30. The second tether 30 is coupled on oneend to the payload 26 and on an opposite end 32 to a transfer member 34.In the exemplary embodiment, the transfer member 34 is a transfer armthat extends from a side of the fuselage 22. In an embodiment, thetransfer arm may be an expandable or extendable member that may beextended or retracted for the payload transfer process. The expandabletransfer arm may be actuated by hydraulic, pneumatic, electromechanical(motor with a power screw) or with magnetic (solenoid or linearactuator) assemblies.

In an embodiment, the end 32 is movably or slidably coupled to thetransfer member 34 to allow the end 32 to move from the transfer member34 to another transfer member on another drone or a stationary dockingstation. In an embodiment, the movement of the end 32 is under theinfluence of gravity. In an embodiment, the transfer member 34 includesa coupling device 36. As discussed herein, in some embodiments thecoupling device 36 engages a coupling device on another drone during thepackage transfer process to maintain the pair of drones in a fixedrelationship during the transfer process. In the exemplary embodiment,the coupling device 36 is an electromagnet. In other embodiments thecoupling device 36 may be any suitable mechanical, electro-mechanical ormagnetic mechanism for engaging another drone.

The drone 20 includes a controller 38 having a processing circuit. Thecontroller 38 may include processors that are responsive to operationcontrol methods embodied in application code such as those shown inFIGS. 14-15. These methods are embodied in computer instructions writtento be executed by the processor, such as in the form of software. Thecontroller 38 is coupled transmit and receive signals from the thrustdevices 24, the transfer member 34 and the coupling device 36 todetermine and change their operational states (e.g. extend transfermember 34, change polarity of coupling device 36, adjust lift fromthrust devices 24). The controller 38 may further be coupled to one ormore sensor devices that enable to the controller to determine theposition, orientation and altitude of the drone 20. In an embodiment,these sensors may include an altimeter 40, a gyroscope or accelerometers42 or a global positioning satellite (GPS) system 44.

FIG. 2 illustrates a block diagram of a controller 38 for use inimplementing a system or method according to some embodiments. Thesystems and methods described herein may be implemented in hardware,software (e.g., firmware), or a combination thereof. In someembodiments, the methods described may be implemented, at least in part,in hardware and may be part of the microprocessor of a special orgeneral-purpose controller 38, such as a personal computer, workstation,minicomputer, or mainframe computer.

In some embodiments, as shown in FIG. 2, the controller 38 includes aprocessor 105, memory 110 coupled to a memory controller 115, and one ormore input devices 145 and/or output devices 140, such as peripheral orcontrol devices, that are communicatively coupled via a local I/Ocontroller 135. These devices 140 and 145 may include, for example,battery sensors, position sensors (altimeter 40, accelerometer 42, GPS44), indicator/identification lights and the like. Input devices such asa conventional keyboard 150 and mouse 155 may be coupled to the I/Ocontroller 135 when the drone is docked to allow personnel to service orinput information. The I/O controller 135 may be, for example, one ormore buses or other wired or wireless connections, as are known in theart. The I/O controller 135 may have additional elements, which areomitted for simplicity, such as controllers, buffers (caches), drivers,repeaters, and receivers, to enable communications.

The I/O devices 140, 145 may further include devices that communicateboth inputs and outputs, for instance disk and tape storage, a networkinterface card (NIC) or modulator/demodulator (for accessing otherfiles, devices, systems, or a network), a radio frequency (RF) or othertransceiver, a telephonic interface, a bridge, a router, and the like.

The processor 105 is a hardware device for executing hardwareinstructions or software, particularly those stored in memory 110. Theprocessor 105 may be a custom made or commercially available processor,a central processing unit (CPU), an auxiliary processor among severalprocessors associated with the controller 38, a semiconductor basedmicroprocessor (in the form of a microchip or chip set), amacroprocessor, or other device for executing instructions. Theprocessor 105 includes a cache 170, which may include, but is notlimited to, an instruction cache to speed up executable instructionfetch, a data cache to speed up data fetch and store, and a translationlookaside buffer (TLB) used to speed up virtual-to-physical addresstranslation for both executable instructions and data. The cache 170 maybe organized as a hierarchy of more cache levels (L1, L2, etc.).

The memory 110 may include one or combinations of volatile memoryelements (e.g., random access memory, RAM, such as DRAM, SRAM, SDRAM,etc.) and nonvolatile memory elements (e.g., ROM, erasable programmableread only memory (EPROM), electronically erasable programmable read onlymemory (EEPROM), programmable read only memory (PROM), tape, compactdisc read only memory (CD-ROM), disk, diskette, cartridge, cassette orthe like, etc.). Moreover, the memory 110 may incorporate electronic,magnetic, optical, or other types of storage media. Note that the memory110 may have a distributed architecture, where various components aresituated remote from one another but may be accessed by the processor105.

The instructions in memory 110 may include one or more separateprograms, each of which comprises an ordered listing of executableinstructions for implementing logical functions. In the example of FIG.2, the instructions in the memory 110 include a suitable operatingsystem (OS) 111. The operating system 111 essentially may control theexecution of other computer programs and provides scheduling,input-output control, file and data management, memory management, andcommunication control and related services.

Additional data, including, for example, instructions for the processor105 or other retrievable information, may be stored in storage 120,which may be a storage device such as a hard disk drive or solid statedrive. The stored instructions in memory 110 or in storage 120 mayinclude those enabling the processor to execute one or more aspects ofthe systems and methods of this disclosure.

The controller 38 may further include a display controller 125 coupledto a user interface or display 130. In some embodiments, the display 130may be an LCD screen. In other embodiments, the display 130 may includea plurality of LED status lights. In some embodiments, the controller 38may further include a network interface 160 for coupling to a network165. The network 165 may be an IP-based network for communicationbetween the controller 38 and an external server, client and the likevia a broadband connection. In an embodiment, the network 165 may be asatellite network. The network 165 transmits and receives data betweenthe controller 38 and external systems. In an embodiment, the externalsystem may be another aerial drone or a drone docking system, whereinthe transmitting and receiving of data allows the controller 38 toidentify the other drone or docking system and determine when thepayload is to be transferred to the other drone. In some embodiments,the network 165 may be a managed IP network administered by a serviceprovider. The network 165 may be implemented in a wireless fashion,e.g., using wireless protocols and technologies, such as WiFi, WiMax,satellite, etc. The network 165 may also be a packet-switched networksuch as a local area network, wide area network, metropolitan areanetwork, the Internet, or other similar type of network environment. Thenetwork 165 may be a fixed wireless network, a wireless local areanetwork (LAN), a wireless wide area network (WAN) a personal areanetwork (PAN), a virtual private network (VPN), intranet or othersuitable network system and may include equipment for receiving andtransmitting signals.

Systems and methods according to this disclosure may be embodied, inwhole or in part, in computer program products or in controller 38, suchas that illustrated in FIG. 2.

Referring now to FIG. 3, an embodiment is shown of a package or payloaddelivery system 200 that uses autonomous drones, such as drone 20 forexample, to deliver a payload from an originating location 202 (e.g. awarehouse) to a final destination 204 (e.g. a customer). In anembodiment, the system 200 is configured to provide delivery of thepayload 26 to destination locations where the drone 20 that initiallyreceives the payload is unable to complete the delivery. The drone 20may be unable to complete the delivery for a variety of reasons, forexample, the destination location 204 may be beyond the range of thedrone 20 (e.g. too far way). The drone 20 may not be able to completethe delivery for other reasons as well; the use of the drone 20 may berestricted by governmental regulations or due to geographic restrictionsby contracts between parties for example. In still other embodiments,the destination location 204 may only allow deliveries from approveddrones.

In this embodiment, the system 200 provides for the in-flight transferof the payload 26 from an initial drone 20 to one or more intermediatedrones 206, 208 or a docking system 210. The system 200 provides for thein-flight transfer to allow the drones 20, 206, 208 to transfer thepayload 26 without landing and therefore improving the efficiency of thedelivery. In an embodiment, the system 200 includes a communicationsystem 212 that allows the transmission of signals to the drones 20,206, 208, such as through a satellite based communications link 214. Itshould be appreciated that the communications link 214 may be cellular,radio frequency or a mesh communications type network. The signalstransmitted to the drones 20, 206, 208 may include locations to pick up,transfer or deliver the payload, or the size and weight of the payloadfor example. The signals transmitted to the drones 20, 206, 208 mayfurther include identification information that allows the carryingdrone (e.g. drone 20) to dynamically identify the receiving drone (e.g.drone 206) prior to engaging in the in-flight transfer process.

Referring now to FIGS. 4-7 an embodiment of a drone 220 is shown that isconfigured to carry a payload 26 and perform an in-flight transfer ofthe payload 26 to another drone 240 or a docking platform 210. The drone220 as the original carrier of the payload 26 may be referred to as theoriginating drone. In this embodiment, the drone 220 includes aplurality of thrust devices 222 that provide lift, horizontal thrust andorientation control. A transfer arm 224 extends from the fuselage 226.It should be appreciated that the transfer arm 224 is positioned as tonot interfere with the thrust devices 222. In the exemplary embodiment,the transfer arm 224 is extendable and retractable. In embodiments, thisprovides for a more aerodynamic profile and reduces drag to increaseefficiency and range. On the end of the transfer arm 224 is a couplerdevice 228, such as an electromagnet. As discussed above the transferarm 224 and coupler device 228 may be controlled by the controller 38.In an embodiment, the controller 38 may change the polarity of theelectromagnet to allow the coupler device 228 to engage another couplerdevice.

The payload 26 is coupled to the fuselage 226 by a first tether 230. Inan embodiment, the payload 26 is releasably coupled to the first tether230, such as at end 232 for example. The release device for payload 26may be reusable (e.g. a magnetic based system) or a one-time usage (e.g.the first tether 230 is severed or includes a frangible joint). Thepayload 26 is further coupled to a second tether 234. The second tether234 includes an end 236 that is slidably coupled to the transfer arm224. In an embodiment, the end 236 includes a capture ring 238. Thecapture ring 238 may be sized to allow the capture ring 238 to freelymove along the length of the transfer arm 224.

In operation, the originating drone 220 receives a payload 26 (i.e. froma warehouse or another drone) and travels to the location of thetransfer. In an embodiment, the originating drone 220 receives data,such as upon receiving the payload 26 or while enroute to the transferlocation, that indicates the identity of the receiving drone 240 ordocking platform 210. Upon reaching the transfer location, theoriginating drone 220 identifies the receiving drone 240. Theidentification may occur via radio frequency (RF) communication forexample. In one embodiment, each of the drones 220, 240 have atransponder that communicates an identification signal. In anembodiment, the drones 220, 240 may include a radio frequencyidentification device (RFID) that transmits the identification signal.In other embodiments, the identification may occur optically, such asvia a camera that is used to acquire images of the other drone and themarkings are visually compared to determine identification. In stillother embodiments, the drones 220, 240 may include lights or LED's thatare used to transmit an identification signal to the other drones.

In this embodiment, the receiving drone 240 also includes a transfer arm242 having a coupling device 244 arranged on the end. The transfer arm242 may be extendible and retractable as discussed herein with respectto arm 224. Once the identification has been validated, the drones 220,240 align their fuselages 226, 246 such that the transfer arms 224, 242and coupling devices are aligned. The alignment of the transfer arms224, 242 may be accomplished by adjusting the respective thrust devices222, 248. Once aligned, the drones 220, 240 engage the coupling devices228, 244 (FIG. 5). Once the coupling devices 228, 244 are engaged, thedrones 220, 240 are fixedly coupled to each other. In an embodiment, therespective controllers 38 establish a communication linkage, such as viaradio frequency or a data connection in the coupling devices 228, 244for example, that allows the controllers 38 to cooperate and maintain acoordinated altitude and orientation.

At the point of engagement, the capture ring 238 is positioned on thetransfer arm 224 of the originating drone 220. The drones 220, 240 thenchange their respective orientations (FIG. 6) to tilt or angle thecoupled transfer arms 224, 242 to allow the capture ring 238 to move orslide along the length of the transfer arms 224, 242 from the transferarm 224 to the transfer arm 242 under the influence of gravity. Itshould be appreciated that once the capture ring 238 moves, the payload26 is coupled to the originating drone 220 by the first tether 230 andto the second drone 240 by the second tether 234.

In an embodiment, the controllers 38 determine the change in orientationto allow the capture ring 238 to move and for the payload to transferbased on the weight of the payload, a desired transfer rate, and alength of transfer. Other variables may include factors such as thecoefficient of friction between the capture ring 238 and the transferarms 224, 242. The controllers 38 then determine a mass transfertime-dependent differential vector. For example, it may be known that a250 g payload is to be transferred at a rate of 3 cm/second over a spanof 30 cm. From this differential vector, an orientation or altitudeadjustment may be determined to provide a desired or predeterminedtransfer rate or dynamic load shifting. As discussed further herein, thedrones 220, 240 may include dynamic counterbalancing. The determineddifferential vector may be used to determine the timing and amount ofdynamic counterbalancing that is applied.

With the capture ring 238 moved, the drones 220, 240 again adjust theirorientations, such as to a relatively horizontal position for example,and disengage the coupling devices 228, 244 (FIG. 7). The originatingdrone 220 may then release the payload 26 resulting in the payload 26being coupled to the receiving drone 240 by the second tether 234. Oncereleased, the payload 26 moves into alignment with the receiving drone240. In an embodiment, the receiving drone 240 may couple a third tether250 to secure the payload 26. The drones 220, 240 may then retract theirrespective transfer arms 224, 242 and proceed to their next destination.

It should be appreciated that the transferring of the payload 26 fromthe originating drone 220 to the receiving drone 240 results in atransfer of weight from one drone to the other. During the transitionperiod during which the payload is being transferred, the center ofgravity of each respective drone 220, 240 will be dynamically changingas the weight shifts from one drone to the other. In an embodiment, thecontrollers 38 compensate for the dynamic changing of the center ofgravity by adjusting the thrust devices 222, 248. In an embodiment wherethe drones 220, 240 have a plurality of thrust devices 222, 248 (e.g.four thrust devices arranged about the periphery of the drone), thecontrollers 38 may adjust individual thrust devices 222, 248 differentlyand continuously during the transfer process of payload 26 to maintain apredetermined altitude and orientation.

In another embodiment shown in FIG. 8, the drones include a dynamiccounterbalance member 252 in the form of a second arm 258 that isarranged opposite the transfer arm 242. The second arm 258 may beextendable or retractable in the direction indicated by arrow 256. Aweight member 254 is disposed on the end of the second arm 258. Itshould be appreciated that as the second arm 258 is extended furtherfrom the center of the fuselage 246, the center of gravity of the drone240 will shift in the direction of the weight member 254. Since theweight of the payload 26 is being transferred onto the transfer arm 242,the controller 38 may extend or retract the second arm 258 to compensatefor the payload 26 and maintain the center of gravity of the drone 240in a desired location or range of locations.

In another embodiment shown in FIG. 9, another the counterbalance member252 is shown having a plurality of ballast tanks 260A, 260B, 260C thatcontain a balancing fluid. The ballast tanks 260A, 260B, 260C may bedisposed within the fuselage 246 or suspended below the fuselage 246 forexample. The counterbalance member 252 further includes pumps 262 thatare configured to transfer a fluid between the center ballast tank 260Aand the outer ballast tanks 260B, 260C. In this embodiment, tocompensate for the weight from the payload 26, the controller 38 mayactivate the pumps 260 to move fluid from the center ballast tank 260Ato one or more of the outer ballast tanks 260B for example, to maintainthe center of gravity in a desired location. In the illustratedembodiment, as the weight of the payload 26 is transferred onto thetransfer arm 242, the fluid is moved from the ballast tank 260A, 260Ctowards the ballast tank 260B.

In an embodiment, the drone may use a combination of the abovecounterbalancing arrangements during operation.

It should be appreciated that while embodiments herein describe andillustrate the transfer process with respect to a single payload 26, inother embodiments, the transfer process may include multiple payloads.Referring now to FIG. 10, an embodiment is shown wherein the originatingdrone 220 is carrying multiple payloads 26A, 26B. Each of the payloads26A, 26B may be individually coupled to the fuselage 226 by the firsttether 230, or may be jointly coupled. Each payload 26A, 26B is coupledby a separate second tether 234A, 234B. Each second tether 234A, 234Bincludes a capture ring 238A, 238B. To transfer the payloads 26A, 26B,the drones 220, 240 perform the steps discussed herein with respect toFIGS. 4-7. It should be appreciated however, that the drones 220, 240may also be configured to transfer one of the payloads, such as payload26B for example, from the originating drone to the receiving drone 240.In an embodiment, the capture rings 238A, 238B may be selectivelycoupled to the transfer arm 224 to retain the capture ring and preventit from moving onto the transfer arm of the receiving drone 240. In thismanner, the retained payload (e.g. payload 26A) may be retained on theoriginating drone 220 while the other payload (e.g. payload 26B) istransferred to the receiving drone 240.

Referring now to FIG. 11 an embodiment of an arrangement for engagingthe coupling devices 228, 244. In this embodiment, the end of thetransfer arm 242 of the receiving drone 240 includes a cone member 264.The cone member 264 has a generally frustoconical shaped interior havinga distal end 266 that is larger than the end 268 proximate the couplingdevice 244. In this embodiment, as the drones 220, 240 approach eachother, the transfer arm 224 and the coupling device 228 are received bythe end 266 of the cone member 264. The angled shape of thefrustoconical inner surface guides the coupling device 228 towards thecoupling devices 244. This provides advantages in completing theengagement of the coupling devices 228, 244 in the event there is amisalignment of the drones 220, 240.

Referring now to FIG. 12A, FIG. 12B and FIG. 12C another embodiment isshown of an arrangement for facilitating the coupling of devices 228,244. In this embodiment, the cone member 264 may include a substantiallysolid outer cone made from an elastomeric plastic. In an embodiment, thecone member 264 may be reinforced with springs to keep the cone member264 open. In still another embodiment, the cone member 264 may includesubstantially rigid parallel/co-axial armatures with webbing arrangedbetween the arms. The arms may be gimbally disposed so that each armextends/collapses towards the long axis of the cone as the arms areextended/retracted with respect to the housing of the transfer arm 242.In this embodiment, when the drones 220, 240 are to couple, the drone240 extends the cone member 264 (FIG. 12A). The cone member 264 has agenerally frustoconical shaped interior having a distal end 266 that islarger than the end 268 proximate the coupling device 244. Thefrustoconical shape of the cone member guides the coupling device 228towards the coupling device 244 (FIG. 13A). After the coupling device228 is coupled to the device 244, the drone 240 may retract the conemember 264 (FIG. 12B) until the cone member 264 is disposed withintransfer arm 242 (FIG. 12C, FIG. 13B). With the coupling devices 228,244 connecting the drones 220, 240, the transfer of the payload 26 maybe initiated.

Referring now to FIG. 14A, an embodiment of a system is shown forassisting the transfer of the payload 26 from the originating drone 220to the receiving drone 240. In this embodiment, the receiving drone 240includes a transfer sleeve 400 that moves from a retracted position(e.g. within a housing on the drone 240) to an extended position. Thetransfer sleeve 400 is generally tubular in shape having a hollowinterior that is sized to receive the transfer arm 242. On an end 402,the transfer sleeve 400 includes a pickup member 404 that moves with thetransfer sleeve 400 as the transfer sleeve is extended and retracted.The transfer sleeve 400 is sized to extend over the transfer arm 224(FIG. 14A) until the pickup member 404 is proximate the capture ring 238(FIG. 14B).

In an embodiment, the pickup member 404 and the capture ring 238 areconfigured to interlock and couple when the members 404, 406 areproximate each other. In one embodiment, the interlock may be formed byan electromagnet. In another embodiment, the interlock may be formed bya mechanical means, such as a spring-loaded latch for example. Once themember 404 and capture ring 238 are interlocked, the transfer sleeve isretracted such that the end 402 moves towards the fuselage of the drone240. As the transfer sleeve 400 is retracted, the interlocking of themember 404 and capture ring 238 causes the payload 26 to move away fromthe originating drone 220 and towards the receiving drone 240 (FIG.14C). In one embodiment, the use of the transfer sleeve 400 allows forthe transfer of the payload from the originating drone 220 to thereceiving drone 240 without reorienting (angling) the drones 220, 240.In another embodiment, the use of the transfer sleeve 400 reduces theamount of orientation change used in the transfer process.

When the transfer sleeve 400 is fully retracted (FIG. 14D), the member404 and capture ring 238 are disposed on the transfer arm 242 and thetransfer of the payload 26 from the originating drone 220 to thereceiving drone 240 is completed. The coupling device 228 may thendisengage from the coupling device 244 allowing the drones 220, 240 toseparate. The payload 26 may then be secured to the receiving drone 240as discussed herein.

Referring now to FIG. 15A, another embodiment is shown for transferringthe payload 26 from the originating drone 220 to the receiving drone240. This embodiment is similar to that of FIG. 14A with the receivingdrone 240 having a transfer sleeve 400 that is extendable andretractable over the transfer arms 224, 242. The transfer sleeve 400includes a pickup member 404 disposed on an end 402. In this embodiment,the originating drone 220 also includes a transfer sleeve 410. Thetransfer sleeve 410 is also movable between an extended position and aretracted position. On one end 412, a pickup member 414 is coupled tothe transfer sleeve 410. The transfer sleeve 410 is generally tubular inshape having a hollow interior that is sized to receive the transfer arm224.

In the exemplary embodiment, the pickup member 414 includes an interlockdevice, such as an electromagnet or a mechanical locking means (e.g. aspring-loaded latch) for example, that couples the pickup member 414 tothe capture ring 238 (FIG. 15A). As the transfer sleeve 410 moves fromthe retracted position to the extended position, the capture ring 238,and thus the payload 26 are moved along the transfer arm 224. When theoriginating drone 220 is coupled to the receiving drone 240, the capturering 238 and payload 26 are moved towards the receiving drone 240. Itshould be appreciated that movement of the capture ring 238 with thepickup member 414 may also be used at the point of delivery to slide thecapture ring 238 off the transfer arm 224 to disconnect the payload 26from the originating drone 220.

As the capture ring 238 is moved it will come into contact with thepickup member 404 from the receiving drone (FIG. 15B). The interlockdevice of pickup member 404 (e.g. an electromagnet) couples with thecapture ring 238 resulting in the capture ring 238 being coupled to bothpickup members 404, 414. Once the capture ring 238 is coupled to thepickup members 404, 414, the transfer sleeve 410 continues to extendwhile the transfer sleeve 400 retracts. This allows the movement of thecapture ring 238 from the transfer arm 224 onto the transfer arm 242(FIG. 15C). At this point, the weight of payload 26 has been transferredfrom the originating drone 220 to the receiving drone 240.

When the transfer sleeve 400 is fully retracted (FIG. 15D), the member404 and capture ring 238 are disposed on the transfer arm 242 and thetransfer of the payload 26 from the originating drone 220 to thereceiving drone 240 is completed. The coupling device 228 may thendisengage from the coupling device 244 allowing the drones 220, 240 toseparate. The payload 26 may then be secured to the receiving drone 240as discussed herein.

Referring now to FIG. 16 another embodiment of a system for moving thecapture ring 238 from the originating drone 220 to the receiving drone240 without using or without relying on gravity. In this embodiment, thereceiving drone 240 includes a hook member 270 that extends from oralong the transfer arm 242. The hook member 270 includes a curved end272 having an end 276 that defines an open section 274. In thisembodiment, when the transfer arms 224, 242 are engaged, the hook member270 extends and routes the end 276 through the opening defined by thecapture ring 238. This allows the capture ring 238 to pass through theopen section 274 and be captured by the hook member 270. The hook member270 may then be retracted resulting in the loop member being moved fromthe transfer arm 224 of the originating drone 220 to the transfer arm242 of the receiving drone 240.

It should be appreciated that other mechanisms may be used to transferthe capture ring 238, such as but not limited to a conveyor means, amotor-driven means, a pulley system, an electromagnetic means and othermechanical means.

Referring now to FIG. 17 another embodiment is shown for transferring apayload 26 from an originating drone 300 to a receiving drone 302. Boththe originating drone 300 and the receiving drone 302 include aplurality of thrust devices 301, 303. In this embodiment, theoriginating drone 300 includes a movable transfer member 304 arrangedabove the fuselage 306. The transfer member 304 includes a set oftransfer posts 308 that move the payload 26 from a first position withinthe fuselage 306 to a second position for transfer. In an embodiment,the transfer posts 308 are configured to extend through and are movablethe fuselage 306. As will be discussed in more detail below, theextension of the transfer posts 308 through the fuselage 306 allowsdrones 300, 302 to use the transfer posts 308 for both passing andreceiving the payload 26. In an embodiment, the transfer member 304 alsoincludes a guide plate 309 that is movable between an open position(when receiving a payload) and a closes position (when flying or passingthe payload). In an embodiment, the payload 26 is arranged within acargo cage.

The receiving drone 302 includes a transfer member 310. In anembodiment, the receiving drone 302 is configured and constructedsubstantially identical to the originating drone 300. The drone 302includes a transfer member 310 having a plurality of transfer posts 311that are movable between a raised position over the fuselage 312 and alowered position. The transfer member 310 further includes a guide plate313 that is movable between a closed position and an open position. Inan embodiment, the guide plate 313 is includes a plurality of plates.

Referring now to FIGS. 14A-14D, the sequence or process for transferringthe payload between the originating drone 300 and the receiving drone302 is shown. After performing the identification authenticationdiscussed herein, the drones 300, 302 first prepare and reconfigure forthe transfer. The originating drone 300 extends the transfer posts 308causing the payload 26 to move from within the fuselage 306 to aposition vertically above the fuselage 306 (FIG. 18A). At this point,the receiving drone 302 also opens the guide plates 313 to define anopening in the fuselage 312 that is sized to receive the package 26.

Next the drones 300, 302 align vertically to each other. As thereceiving drone 302 lowers over the originating drone 300, the guideplates align the elevated cargo cage on originating drone 300 with cargohold in the fuselage 312 (FIG. 18B). As the receiving drone 302approaches the payload 26, locking plates 314 (FIG. 18C) engage thecargo cage of payload 26. The locking plates 314 secure the payload tothe receiving drone 302. Once the locking plates 314 are engaged withthe top of the cargo cage, the originating drone 300 releases the cargocage. With the payload 26 secured to the receiving drone 302, the drones300, 302 disengage and separate (FIG. 18D).

In an embodiment, at the point of separation, the payload 26 is disposedvertically below the receiving drone 302. Referring now to FIGS.19A-19D, a sequence of process for securing the stowing the payload 26within the receiving drone 302. To stow the payload 26, the drone 302first lowers the transfer posts 311 to a lowered position extendingbelow the fuselage 312. Each transfer post 311 includes a latch member315 that engages and locks onto the cargo cage of payload 26 (FIG. 19A).The transfer posts 311 are then moved raising the payload 26 into thecargo area within the fuselage 312. It should be appreciated that beforethe payload 26 is raised, the latching plates 313 are disengaged andthen re-engaged when the payload 26 is within the fuselage 312. In anembodiment, after the latching plates 313 are re-engaged the transferposts 311 are lowered to an intermediate position.

The guide plates 313 are then moved to a closed position, enclosing thebottom of the fuselage 312 (FIG. 19C). At this point, the payload 26 issecured and the drone 302 is ready to continue the delivery process(FIG. 19D).

In some embodiments, one issue that may be encountered with verticalpackage transfer configuration is the thrust/lift reduction for thethrust devices 301 on the lower drone 300 shown in FIG. 20 while it ishovering below the upper drone 302 due to the airflow caused by thethrust devices 303. In one embodiment, the reduction in thrust/lift forthe thrust devices 301 on the lower drone 300 can be compensated byincreasing the rotor speed of the thrust device 301. In anotherembodiment the reduction in thrust/lift for the thrust devices 301 onthe lower drone 300 can be compensated by adjusting the angled thrustdevice mounts 316, 317 on both drones 300, 302 to increase the clean airstream available to the rotors on the lower drone 300. The angling ofthe thrust device mounts 316 may be angled such that the downwash airflow is beneath the drone 300 as indicated by arrows 318. The thrustdevice mounts 317 are then angled in the opposite manner such that thedownwash air flow is directed more outward as indicated by the arrows319 and not directly onto the lower drone 300.

It should be appreciated that the transfer of a payload from drone 302to drone 300 may also be accomplished by performing the transfer processin reverse.

Referring now to FIG. 21, a method 320 is shown for the in-flighttransfer of a payload between drones. The method starts in block 322 andproceeds to block 324 where the drones align themselves to each other.For example, where the drones have transfer arms, the transfer arms areextended and aligned. The method 320 then proceeds to block 326 wherethe transfer members engage each other to couple the drones together. Inan embodiment, the drones communicate while engaged and cooperate tomaintain a desired altitude and orientation. In another embodiment, thedrones act in an arrangement wherein one of the drones assumes controlof the combined operation of the coupled drones for the duration of thetransfer.

The method 320 then proceeds to block 328 where the drones changeorientation, such as increasing the altitude of the originating drone tocreate a slope or angled surface along the length of the engagedtransfer arms. When the orientation is changed, a capture ring of atether slides from the transfer arm of the originating drone to thetransfer arm of the receiving drone. In an embodiment, the sliding ofthe capture ring occurs due to gravity. In another embodiment, the loopportion movement is caused by a member of either the originating droneor the receiving drone, such as a hook member for example. When the loopportion is coupled to the receiving drone, the originating dronereleases the payload tether, allowing the payload to move under theinfluence of gravity. In some embodiments, the payload will fall awayfrom the originating drone for a short distance before the tension ofthe tether connected to the receiving drone causes the payload to swingunder the receiving drone.

With the payload transferred to the receiving drone, the method 320proceeds to block 332 where the originating drone and receiving dronedisengage. In the embodiment where one of the drones assumes control ofboth drones during transfer, the control for the other drone is releasedback to the controller of that drone prior to disengagement. The method320 then proceeds to block 334 where the drones continue on with thedelivery activity.

Referring now to FIG. 22, another method 340 is shown for the in-flighttransferring of a payload from an originating drone to a receivingdrone. In this embodiment, the method 340 starts in block 342 andproceeds to block 344 where the originating drone validates the identityof the receiving drone to ensure that the payload is being transferredto the correct drone. This identification may be performed using a radiofrequency communication of an ID code for example. The method 340 thenproceeds to block 346 where the drones are aligned to initiate thepayload transfer. In block 348 the drone controllers determine a masstransfer time-dependent differential vector. The differential vectorprovides a model for the controllers to predict the impact of thetransfer on the drones (such as for counterbalancing for example) andmay also be used to define the orientation or other flight parametersthat the drones will use to make the transfer efficient. In anembodiment, the method 340 then proceeds to block 350 where theoriginating drone and the receiving drone engage and are coupledtogether. The method 340 then proceeds to block 352 where the droneschange orientation to allow the tether to move from the originatingdrone to the receiving drone. It should be appreciated that block 350and block 352 may be omitted in embodiments where the drones do notengage each other, such as where the receiving drone has a transfermember with a net that catches the payload.

The method 340 then proceeds to block 354 where the payload istransferred from the originating drone to the receiving drone. Once thepayload transfer is completed, the drones disengage in block 356. Themethod 340 ends in block 358 with the drone continuing the deliveryactivities.

It should be appreciated that while embodiments herein describe thepackage transfer process in terms of a transfer between a pair of aerialdrones, the claims should not be so limited. In other embodiments, thetransfer may be between an aerial drone and a stationary object, such asa roof of a building, a drone docking station or other structureconfigured to receive payloads. The transfer of the payload to astationary structure while keeping the drone airborne provides similaradvantages in efficiency of operation as between two aerial drones.

Technical effects and benefits of some embodiments include the efficientin-flight transfer of payloads from an originating drone to a receivingdrone to allow the delivery of a payload where the originating drone isunable to travel to the end destination.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

The corresponding structures, materials, acts, and equivalents of allmeans or step plus function elements in the claims below are intended toinclude any structure, material, or act for performing the function incombination with other claimed elements as specifically claimed. Thedescription of the present invention has been presented for purposes ofillustration and description, but is not intended to be exhaustive orlimited to the invention in the form disclosed. Many modifications andvariations will be apparent to those of ordinary skill in the artwithout departing from the scope and spirit of the invention. Theembodiments were chosen and described in order to best explain theprinciples of the invention and the practical application, and to enableothers of ordinary skill in the art to understand the invention forvarious embodiments with various modifications as are suited to theparticular use contemplated.

The present invention may be a system, a method, and/or a computerprogram product. The computer program product may include a computerreadable storage medium (or media) having computer readable programinstructions thereon for causing a processor to carry out aspects of thepresent invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, or either source code or object code written in anycombination of one or more programming languages, including an objectoriented programming language such as Java, Smalltalk, C++ or the like,and conventional procedural programming languages, such as the “C”programming language or similar programming languages. The computerreadable program instructions may execute entirely on the user'scomputer, partly on the user's computer, as a stand-alone softwarepackage, partly on the user's computer and partly on a remote computeror entirely on the remote computer or server. In the latter scenario,the remote computer may be connected to the user's computer through anytype of network, including a local area network (LAN) or a wide areanetwork (WAN), or the connection may be made to an external computer(for example, through the Internet using an Internet Service Provider).In some embodiments, electronic circuitry including, for example,programmable logic circuitry, field-programmable gate arrays (FPGA), orprogrammable logic arrays (PLA) may execute the computer readableprogram instructions by utilizing state information of the computerreadable program instructions to personalize the electronic circuitry,in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the block may occur out of theorder noted in the figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

The descriptions of the various embodiments of the present inventionhave been presented for purposes of illustration, but are not intendedto be exhaustive or limited to the embodiments disclosed. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope and spirit of the describedembodiments. The terminology used herein was chosen to best explain theprinciples of the embodiments, the practical application or technicalimprovement over technologies found in the marketplace, or to enableothers of ordinary skill in the art to understand the embodimentsdisclosed herein.

What is claimed is:
 1. A system comprising: a first aerial drone havinga first transfer member and a first controller, the first transfermember having a first coupling device on one end, the first transfermember being configured to carry a payload, the first controllerincluding a processor configured to change a first altitude and firstorientation of the first aerial drone; a second aerial drone having asecond transfer member and a second controller, the second transfermember having a second coupling device on one end, the second transfermember being configured to receive the payload, the second controllerincluding a processor configured to change a second altitude and asecond orientation of the second aerial drone; and wherein the firstcontroller and the second controller cooperate to change at least one ofthe first orientation and the second orientation to operably engage thefirst coupling device to the second coupling device for transferring thepayload from the first transfer member to the second transfer memberwhile the first aerial drone and second drone are in-flight.
 2. Thesystem of claim 1 wherein the first transfer member is a first armextending from the first aerial drone and the second transfer member isa second arm extending from the second aerial drone.
 3. The system ofclaim 2 further comprising a first tether slidably coupled on a firstend to the first arm and coupled on an opposing end to the payload,wherein the first end is configured to slide from the first arm to thesecond arm when the first arm is engaged with the second arm.
 4. Thesystem of claim 3 wherein the first controller is configured to changethe first orientation and the second controller is configured to changethe second orientation to slide the first tether from the first arm tothe second arm under an influence of gravity.
 5. The system claim 2wherein: the first coupling device is a first electromagnet and thesecond coupling device is a second electromagnet; and the firstcontroller and the second controller cooperate to change polarities ofthe first electromagnet and the second electromagnet to engage anddisengage the first electromagnet and the second electromagnet.
 6. Thesystem of claim 1 wherein: the first aerial drone includes a movablefirst counterbalance member; the second aerial drone includes a movablesecond counterbalance member; the first controller is operably coupledto change a first position of the first counterbalance member inresponse to the payload transferring from the first aerial drone to thesecond aerial drone to maintain the first aerial drone at a firstpredetermined orientation; and the second controller is operably coupledto change a second position of the second counterbalance member inresponse to the payload transferring from the first aerial drone to thesecond aerial drone to maintain the second aerial drone at a secondpredetermined orientation.
 7. The system of claim 6 wherein the firstcounterbalance member is moveable between a first retracted and a firstextended position, wherein the first retracted position is closer to acenter of the first aerial drone than the first extended position. 8.The system of claim 7 wherein the second counter balance member ismovable between a second retracted position and a second extendedposition, wherein the second retracted position is closer to a center ofthe second aerial drone than the second extended position.
 9. The systemof claim 6, wherein the first counterbalance member includes a firstplurality of ballast tanks and a first fluid disposed in at least one ofthe second plurality of ballast tanks.
 10. The system of claim 9,wherein the second counterbalance member includes a second plurality ofballast tanks and a second fluid disposed in at least one of the secondplurality of ballast tanks.
 11. An aerial drone comprising: a fuselage;a plurality of thrust producing devices coupled to the fuselage; atransfer member coupled to the fuselage, the transfer member configuredto move a payload to a second aerial drone; and a controller operablycoupled to the plurality of thrust producing devices, the controllerincluding a processor that is responsive to executable computerinstructions to adjust the plurality of thrust producing devices tochange an orientation of the transfer member to move the payload to asecond aerial drone.
 12. The system of claim 11 further comprising: amovable counterbalance member; and wherein the controller is operablycoupled to change a position of the counterbalance member in response tothe payload moving to the second aerial drone to maintain the aerialdrone at a predetermined orientation.
 13. The system of claim 12 whereinthe counterbalance member is moveable between a retracted and anextended position, wherein the retracted position is closer to a centerof the aerial drone than the extended position.
 14. The system of claim11, wherein the counterbalance member includes a plurality of ballasttanks and a fluid disposed in at least one of the plurality of ballasttanks.
 15. A method of in-flight transferring of a payload betweenaerial drones, the method comprising: providing a first aerial dronehaving a first transfer member; providing a second aerial drone having asecond transfer member; changing at an orientation of at least one ofthe first aerial drone and the second aerial drone to position the firsttransfer member adjacent the second transfer member; and moving thepayload from the first aerial drone to the second aerial drone.
 16. Themethod of claim 15, wherein: the first aerial drone includes a movablefirst counterbalance member; the second aerial drone includes a movablesecond counterbalance member;
 17. The method of claim 16, furthercomprising: changing a first position of the first counterbalance memberto maintain the first aerial drone at a first predetermined orientationin response to the payload transferring from the first aerial drone tothe second aerial drone; and changing a second position of the secondcounterbalance member to maintain the second aerial drone at a secondpredetermined orientation in response to the payload transferring fromthe first aerial drone to the second aerial drone.
 18. The method ofclaim 17, wherein the changing of the first position includes moving thecounterbalance between a first retracted and a first extended position,wherein the first retracted position is closer to a center of the firstaerial drone than the first extended position.
 19. The method of claim18, wherein the changing of the second position includes moving thesecond counter balance member between a second retracted position and asecond extended position, wherein the second retracted position iscloser to a center of the second aerial drone than the second extendedposition.
 20. The method of claim 17, further comprising: wherein thechanging of a first position includes moving a first fluid between afirst plurality of ballast tanks operably coupled to the first aerialdrone; and wherein the changing of the second position includes moving asecond fluid between a second plurality of ballast tanks operablycoupled to the second aerial drone.